Former racehorses are the latest weapons on the frontline of South Africa’s war with rhino poachers, amid growing calls for the horns to be traded legally.

The horses are being used in riding patrols to track poachers, as fears grow that South African rhinos are on the brink of a catastrophic population decline.

With rhino poaching hitting a record level last year, many of those battling to save the animal say legalising the trade in rhino horn is the only option.

Ranger Tim Parker heads the anti-poaching unit on a wildlife reserve west of the world-famous Kruger National Park and says several times a week horse-riding rangers traverse the dry expanse with a single mission - to catch the poachers.

"They offer a lot more diversity than just walking," Mr Parker said of the racehorses.

Rhino poaching soars as protection effort steps up

Mr Parker says his team was initially apprehensive about how the horses would adapt in a Big Five reserve.

"It was a new environment for them, so they were seeing animals that they'd never seen before. Walking in terrain that they'd never walked in before. But they settled in remarkably well," he said.

But he says poaching is difficult to stop.

"It's a multifaceted approach. It's not just us soldiers on the ground trying to combat it, because we're basically putting out fires," he said.

You're not harming the animal at all by cutting the horn off at all. So I think if they regulate and have a legalised trade in rhino horn, I think it will certainly have a positive input into saving the species.

Ranger Tim Parker

The number of rhinos killed last year was nearly 950 - a new national record.

South Africa's environment affairs ministry warns that if the trend continues, the wild rhino population could be wiped out within a decade.

Mr Parker says many conservationists and rhino owners now believe that legalising the horn trade is the only answer.

"One of the positive aspects is we have a renewable resource on the rhino: the horns grow back again," he said.

"You're not harming the animal at all by cutting the horn off at all. So I think if they regulate and have a legalised trade in rhino horn, I think it will certainly have a positive input into saving the species."

Advocates wants lucrative trade legalised

Rhino horn is more lucrative than gold and the global ban on the product is failing.

It is a multilayered battle, stemming from the poacher who will do anything to put food on the family table, to the insatiable demand from Asia for a horn long believed to possess medicinal benefits.

The losing battle has led many conservationists and rhino farm owners to call for the trade to be legalised.

South African Private Rhino Owners Association chairman Pelham Jones says if the trade was legalised, the South African government would use the proceeds to aid rhino protection and preservation.

"The trade would be done via an international platform where the origin of each horn has been certified from source by DNA, thus preventing 'Blood Horns' from entering the legal trade market," he said.

But Environmental Investigation Agency executive director Mary Rice, says legalising the trade would not stop poaching and illegal trading, drawing on the pitfalls of the ivory trade.

"Increasing the availability and visibility of a product in a market stimulates and increases demand and, thereby, expands markets," she said.

"And legal markets cannot be effectively regulated – the much-heralded ivory control and regulation system in China has been a monumental failure.

"Traders, legal and illegal, regularly abuse the system and there is now more illegal ivory on the market place in China than there is legal ivory."

She says current bans needs to reach beyond law enforcement on the ground and focus on the "middle men".

"The same methodologies applied to other serious organised crimes – intelligence led and multi-disciplinary – are tried and tested and need to be applied to wildlife crime," she said.

As the horse patrol draws to an end, they are de-saddled and led into their predator-proof stables.

While the days of racing to a marked destination have passed, the horses pursue an elusive finish line - one they alone cannot conquer.